Mozilla FirefoxMozilla Firefox is the ubiquitous web browser. Based on open source components, it is trademarked and cannot be altered or re-distributed with any change that involves the name or trademarks. Install the current version: sudo apt-get install firefox

IceCatGNU IceCat, formerly known as GNU IceWeasel, is a web browser distributed by the GNU Project. IceCat, which is made entirely of free software, is a fork of Mozilla Firefox. It is compatible with the GNU/Linux operating system. Install the current version: sudo apt-get install iceape-browser

SeaMonkey
The SeaMonkey project is a community effort to develop the SeaMonkey all-in-one internet application suite (see below). Such a software suite was previously made popular by Netscape and Mozilla, and the SeaMonkey project continues to develop and deliver high-quality updates to this concept. Containing an Internet browser, email & newsgroup client, HTML editor, IRC chat and web development tools, SeaMonkey is sure to appeal to advanced users, web developers and corporate users. Install the current version: sudo apt-get install seamonkey

IceApeIceApe is an open source Internet suite, based upon the defunct Mozilla Suite (now itself folded into the SeaMonkey suite).Anyone familiar with Gecko-based Internet suites, such as the original Netscape browser/suite or Mozilla's, will feel comfortable with IceApe's interface and contents. Install the current version: sudo apt-get install iceape

OperaOpera is a proprietary browser and internet suite (currently free on PCs) also used in some mobile devices and gaming consoles. It includes email, an address book, IRC chat, integrated BitTorrent, and webfeeds. A limited number of plugins are also available: sudo apt-get install opera